What is the first step you should take before replacing a section of damage pipe on a live main?

Before replacing a section of damaged pipe on a live main, the most critical first step is to stop the gas flow. This action is vital for ensuring safety during the repair process. When working on a live gas main, the risk of gas leaks is significantly increased, potentially leading to dangerous situations such as fires or explosions. By stopping the gas flow, you eliminate the immediate hazard, allowing you to perform the necessary repairs safely.

Addressing this step first is essential because even with notifications or safety measures in place, the danger posed by gas escaping during the repair process is paramount. Thus, halting the gas flow must be prioritized before considering any further actions such as notifying emergency services or inspecting the area for safety concerns.